So... whaddaya think?

> Subsidence?
> vandalism?

If there aren't any caps on the PVC casings and the rods are smooth rods only 10 ft. or so in length, is frost heave plausible as the main culprit?

> If there aren't any caps on the PVC casings and the rods are smooth rods only 10 ft. or so in length, is frost heave plausible as the main culprit?
The datasheet for C445 says it is 20 feet long.

I still think it is frost heave. That is why the stainless steel rods installed today have the top few feet in a grease filled tube.

> The datasheet for C445 says it is 20 feet long.

And that's one where the cap and rod have separated, but the cap hasn't been collected as a souvenir, which any self-respecting vandal would want to do. It's hard to tell how the drainage pattern works, i.e. if the PVC pipe "well" could have filled up with water which then froze. I'm unfamiliar with how that type of monument is put together, but the caps look as if they were attached to the rods by crimping the stems of the caps. If that's right, the crimp could have initiated a crack where the tablet and stem joined.

No h*ll no, its the low-lifes that vandalize these things to take to a re-cycle place to get money for drugs or cigs.

I say give these people all the drugs they want and let the undertaker clean up the mess.

> And that's one where the cap and rod have separated, but the cap hasn't been collected as a souvenir, which any self-respecting vandal would want to do. It's hard to tell how the drainage pattern works, i.e. if the PVC pipe "well" could have filled up with water which then froze. I'm unfamiliar with how that type of monument is put together, but the caps look as if they were attached to the rods by crimping the stems of the caps. If that's right, the crimp could have initiated a crack where the tablet and stem joined.
This is Montana. These things are packed in snow and ice for 4 months every year. Sure, I agree, the PVC could fill with water and then freeze, popping off the caps.

Definitely frost/soils related. I assume the final monument was slowly bent when the cap was still confined by the PVC.

How deep are the PVC casings?

Steve

Freeze thaw action. Had some dam safety monuments at the 8,000 ft. elev. level that were set in concrete. The problem was the inside of the pipes/caps were never filled with concrete to the top. First good thaw freeze action and the caps pop off like a champagne cork. :-O

Pablo B-)

I've seen USGS (not NGS) disk-on-rod marks in Iowa that appear to have sprouted like flowers. I can't find a good picture right now, but here's a small part of the area photo for one. At the time I logged it I attributed the situation to regrading, but now I tend to think frost heave.

Ah, here's another one a few miles from the first.

I'm thinking that it's a frost issue also- haven't observed these yet to see what kind of eelevations we get. H445 with bentrod is the one that has me scratching my head about- what made it bend instead of just heaving up?

> H445 with bentrod is the one that has me scratching my head about- what made it bend instead of just heaving up?
It could have been bent like that when it was driven.

> > H445 with bentrod is the one that has me scratching my head about- what made it bend instead of just heaving up?
> It could have been bent like that when it was driven.

If rights-of-way beyond the pavement are mowed in Montana as they are in Texas, my first thought would be a tractor wheel did that, driving over the capped rod that was jacked up from the frost. The witness post sign showing distress looks like a mower or piece of machinery brushed it.